Process for the preparation of indigo dyed yarn for use in the manufacture of knitted fabric

ABSTRACT

A process for the preparation of indigo dyed yarn for use in the manufacture of knitted fabric by a knitting machine comprising in the steps of, forming a dyed rope of yarn by the steps of indigo dyeing; individualizing the yarn of said dyed rope; forming separate packages of the yarn on separate spools of fixed ends; preparing individual hanks of each yarn end of each spool by hank maker; converting said hanks into individual cones of single yarn.

FIELD OF THE INVENTION

[0001] This invention relates to a novel process for the preparation ofindigo dyed yarn for use in the manufacture of knitted fabric.

PRIOR ART

[0002] The process of indigo dyeing is known as such in the art. In theknown process, the dyeing of yarn is continuous only on the surfacebecause of oxidation during the process. In such a process, the core ofthe yarn remains undyed and is always in its natural shade. Such aprocess of indigo dyeing is performed at room temperature and underatmospheric pressure. The yarn is dyed in the form of a rope containing240-400 ends throughout its length and is dyed by using a rope dyeingmachine. For this purpose, the rope is first subjected to the process ofscouring at a temperature of 75 to 85° C. and then subjected to thesuccessive steps of hot and cold wash. The washed yarn is then passedthrough a plurality of dye baths, the number of dye baths beingdependent on the colour and the shade. Finally, the yarn is subjected tothe step of hot washing at 60-70° C. followed by cold wash at roomtemperature and then to the step of softening. As will be apparent, theprocess employs an open bath system and yarn is subjected to airoxidation, which is required for surface dyeing of the yarn. The ropewith 240-400 ends and which is subjected to such a step of dyeing isprepared by a warping machine. The dyed rope obtained after the processof dyeing is delivered into a can capable of accommodating upto 100 kgs.of rope.

[0003] The dyed rope with the required ends is then fed to a long chainbeamer to convert the rope into a warper beam and then subjected to thestep of sizing to impart strength so as to withstand friction duringweaving of cloth on a loom. However, prior to the step of sizing, eachend of yarn is individualized and then wound onto a beam widthwise.

[0004] The process described hereinabove was advantageously employed inthe weaving of a fabric in a loom, but could not be employed in aknitting machine for producing a knitted fabric.

OBJECTS OF THE INVENTION

[0005] A primary object of this invention is to propose a process forthe preparation of indigo dyed yarn for use in the manufacture ofknitted fabrics.

[0006] Another object of this invention is to propose a process for thepreparation of indigo dyed yarn in the form of cone where the yarn isreceived in fixed numbers of ends from the dyed rope of 216 ends. On 6individuals spools fitted on the shaft and thus avoiding the use ofWarper Beam.

[0007] Yet another object of this invention is to propose a process forthe preparation of indigo dyed yarn in the form of cone for use in themanufacture of knitted fabric as intermediate or individual spool usedfor shifting the yarn from Warper Beam, cannot be fed directly toknitting machines to knit the fabric and thus avoiding use ofintermediate spools and individuals spools.

[0008] A further object of this invention is to propose a system forpreparation of dyed indigo yarn for manufacture of knitted fabrics. Sofar the process in existence was suitable for weaving i.e. formanufacturing cloth only. Reason is that yarn used to be received onWarper Beamer having 3600 ends to 4000 ends cannot be used on a knittingmachine.

FIELD OF THE INVENTION

[0009] According to this invention, there is provided a process for thepreparation of indigo dyed yarn for use in the manufacture of knittedfabric comprising receiving a dyed yarn from a dyed rope,individualizing the yarns forming said rope, receiving a sheet of saidyarns on its respective spool and such that the yarns from said rope arecollected as a plurality of individual length of yarn on its respectivespool, preparing individual hanks from the respective individual ends ofyarn of the spool, converting said hank into a cone of single yarn byhank to cone maker.

[0010] The process for the preparation of indigo dyed yarn according toa preferred embodiment of this invention is herein described in detailin the following description.

[0011] In accordance with the present invention, a dyed rope is preparedin a manner known as such in the art. In the known process, the dyedrope is fed to a long chain beamer to form a warper beam.

[0012] Such a warper beam could be employed only in the process ofweaving a fabric and not for producing a knitted fabric.

[0013] In distinction to the known art, the dyed yarn from a dyed ropeis received directly on a plurality of spools, such as a set of sixspools, instead of a warper beam in the conventional process. The spoolsare mounted on a warper beam shaft driven by a friction drum which isdriven by a motor independently. Each spool receives, for example, 36ends through warper comb and separator. The machine has a rope vibratorto open the rope into individual yarn and a stop motion device so as tostop the machine in the event of a missing or broken yarn. Six spools of36 ends are produced at a time with, for example, 12-13 kgs. of weightof yarn in each spool. The spools are mounted on a tripod with bearingsand shaft to feed a hank making machine to prepare individual hank fromindividual end of the spool. The spool is self-driven with the yarntension inserted by yarn process while making hank on swift of reelingmachine. In total, 36 hanks are produced in the example referred tohereinabove. This machine is equipped with yarn separators to avoidentanglement of yarn and is driven by motor. The hank is mountedindividually on individual hank holder of hank to cone winding machineto convert hank into cone of single yarn. These machines have stopmotions for hank as well as for cone for end breakage and worksinstantly. Each cone is driven individually through a friction rollerdriven by motor. In the present invention receiving the material (yarn)directly on 6 spools in place of warper beam constitutes an aspect ofinvention and, wherein a cone package of single yarn is converted fromdyed rope of 216 ends.

DESCRIPTION WITH REFERENCE TO DRAWINGS

[0014] Further objects and advantages of this invention will be moreapparent from the ensuing description and wherein

[0015]FIG. 1 shows the machine for formation of yarn into separatespools on a long chain beamer;

[0016]FIG. 2 shows the machine for formation of the hanks; and

[0017]FIG. 3 shows the hank to cone winder.

[0018] As described, a dyed rope of, for example, 222 ends is dyed in amanner known in the art with respect to indigo dyeing of yarn forweaving of a cloth in a loom. However, in the instance of weaving ofcloth in a loom, the yarns of the dyed rope are individualized and thenwound widthwise on a single beam, such steps being effected in a longchain beamer.

[0019] Though a long chain beamer (LCD) of FIG. 1 is also employed inthe present invention, the yarns are no longer wound widthwise on asingle beam. Instead, and if the dyed rope consists of, for example, 222ends, the yarns are divided onto 6 separate beams or spools having 37ends. Each spool has preferably the same number of yarns. Thus, thepackage of dyed rope of 222 ends is divided into 6 separate packages of37 ends. For this purpose, the dyed rope or package 2 ends, for example,of 222 yarn ends from card. Can 1 is fed to a tension stand 3 and thenguided over guide pulleys 4 into an accumulator 5. The rope 2 travelsinto a head stock assembly 6 and finally wound onto aluminium spools 7through separators 8. Though not shown in the drawings, such long chainbeamer LCD has a vibrator to cause an individualization of the yarns anda stop motion device to stop the device in the event of a breakage ofyarn.

[0020] Each spool 7 is mounted on a tripod 9 (see FIG. 2) to feed to ahank maker machine to prepare individual hank from individual yarn endof a spool. The hank maker machine of FIG. 2 comprises a tripod 10 forrotatably holding a shaft 11 on which spool 7 is mounted. The ends passthrough a heald 12 and a stop motion device (not shown) to stop themachine in the presence of a broken end of yarn. A hank 13 is wound onhank maker 14 mounted on a shaft 15. Shaft 15 has a pulley 16 adapted tobe driven by a pulley 17 mounted on drive shaft 18 of a motor 19. Ifeach spool 7 has 37 ends, 37 hanks are formed by the reeling machine ofFIG. 2.

[0021] Each hank 20 is mounted individually on individual hank holder 21of hank to cone winding machine 22 and as illustrated in FIG. 3. Theyarn hank 24 is converted into a cone of single yarn. For this purpose,the yarn 24 from holder 21 passes through a yarn guide pulley 25, atension holding bracket 26 for holding a tensioner and gauge 27 andwound on a paper cone 28.

We claim:
 1. A process for the preparation of indigo dyed yarn for usein the manufacture of knitted fabric by a knitting machine comprising inthe steps of: i. forming a dyed rope of yarn by the step of indigodyeing; ii. individualizing the yarn of said dyed rope; iii. formingseparate packages of the yarn on separate spools of fixed ends; iv.preparing individual hanks of each yarn end of each spool by hank maker;v. converting said hanks into individual cones of single yarn.
 2. Aprocess as claimed in claim 1 wherein each package of yarn formed onsaid spools contain equal number of ends of yarn.
 3. A process asclaimed in claim 1 wherein the number of hanks correspond to the numberof yarn on each spool.
 4. A process as claimed in claim 1 wherein thedyed rope is divided and wound on separate spools in a long chainbeamer.
 5. An apparatus for the preparation of indigo dyed yarn for usein the manufacture of knitted fabric comprising a long chain beamerhaving a plurality of individuals spools for receiving yarn having equalnumber of ends, a hank maker for producing individual hanks and a hankto cone winder.
 6. An apparatus as claimed in claim 5 wherein said longchain beamer has a separator so as to separate the dyed yarn ends andwound on its respective spool.
 7. An apparatus as claimed in claim 6wherein each spool is fed to a hank maker for producing hanks.]
 8. Anapparatus as claimed in claims 6 and 7 wherein said hank maker comprisesa tripod for receiving the spool mounted on a rotatable shaft, a healdfor receiving the yarn from said spool.